Abstract
We propose a systematic method to generate a complete orthonormal basis set of multipole expansion for magnetic structures in arbitrary crystal structure. The key idea is the introduction of a virtual atomic cluster of a target crystal, on which we can clearly define the magnetic configurations corresponding to symmetry-adapted multipole moments. The magnetic configurations are then mapped onto the crystal so as to preserve the magnetic point group of the multipole moments, leading to the magnetic structures classified according to the irreducible representations of crystallographic point group. We apply the present scheme to pyrhochlore and hexagonal ABO3 crystal structures, and demonstrate that the multipole expansion is useful to investigate the macroscopic responses of antiferromagnets.
Highlights
Diversity of physical properties of magnets provides a fascinating playground in condensed matter physics
The magnetic configurations are mapped onto the crystal so as to preserve the magnetic point group of the multipole moments, leading to the magnetic structures classified according to the irreducible representations of the crystallographic point group
We have proposed a scheme to efficiently generate the symmetry-adapted orthonormal magnetic structures in the crystallographic point group by introducing a virtual atomic cluster to perform the multipole expansion
Summary
Diversity of physical properties of magnets provides a fascinating playground in condensed matter physics. We have a significant chance to specify or even design a magnet exhibiting desired physical properties by investigating the order parameters which characterize the magnetic structures. It has been shown that the rank-3 M multipole (octupole) plays a key role for a large AH effect [18,19,20], anomalous Nernst effect [21], and magneto-optical Kerr effect [16] in the coplanar antiferromagnets Mn3Z (Z = Sn, Ge) [7] In these studies, the interplay between the physical properties and the magnetic structure through cluster multipoles has been investigated extensively. The generated complete basis set for the magnetic structure in crystal is useful to measure the symmetry breaking as an order parameter according to the magnetic point group [7]. For the hexagonal ABO3 structure, higher-rank multipoles such as MT quadrupole and M octupole are necessary to describe the magnetic structures exhibiting the AH and EM effects within the uniform magnetic ordering
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
